Cmake - select different c++ standard for different sources

Question

As the title suggest, I'd like to use cmake to build a project, and depending on the source file, enforcing a different c++ standard.

The reason is : I am working on a library and would like to make it c++03 compliant for compatibility, but would like to use Google test suite which requires c++11.

So the unit tests would be compiled with c++11, but I'd like my library to fail at compilation if there is reference to a c++11 only feature.

It has a seance for different targets, but not for each source. — Marek R, Oct 04 '21 at 11:46

score 3 · Accepted Answer · answered Oct 04 '21 at 11:28

So just do that - ompile your library with one standard, and your tests with the other. Nowadays, https://stackoverflow.com/a/61281312/9072753 method should be preferred.

add_library(mylib lib1.cpp)
set_target_properties(mylib
    PROPERTIES
    CXX_STANDARD 03
    CXX_EXTENSIONS off
    )

add_executable(mytest main.cpp)
set_target_properties(mytest
    PROPERTIES
    CXX_STANDARD 11
    CXX_EXTENSIONS off
    )
target_link_libraries(mytest PRIVATE mylib)
add_test(NAME mytest COMMAND mytest)

I'm quite new to cmake. I did not know about the concept of library. Thanks — Pier-Yves Lessard, Oct 04 '21 at 21:51

asmmo · Answer 2 · 2021-10-04T09:32:42.010

1

You can do that, if they are used by different targets, using add_targrt_compile_options , as follows.

Assuming you want to use c++03 with the lib and c++11 with the exec, you may use something like what follows

add_executable(exec1 main.cpp)
add_library(lib1 STATIC lib1.cpp)
target_compile_options(lib1 PRIVATE -std=c++03)
target_compile_options(exec1 PRIVATE  -std=c++11)

edited Oct 04 '21 at 09:32

answered Oct 04 '21 at 06:52

asmmo

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Cmake - select different c++ standard for different sources

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